This invention relates to an image reading apparatus and in particular to a flat-bed image reading apparatus.
Hitherto, an image reading apparatus such as a flat-bed image scanner has been known. In the flat-bed image reading apparatus, a carriage on which an optical system is mounted is moved in parallel to the table face of a document table, whereby the main scanning line is moved in its vertical direction (subscanning direction) for reading a document.
If the fit accuracy of a guide section for positioning a document within a predetermined read area on the table face of the document table and a guide rod for guiding the carriage in the subscanning direction is low, the margin of the document cannot be read or an area where no document exists appears in the margin of the read image.
However, in the flat-bed image reading apparatus in the related art, generally the guide section for positioning a document on the table face of the document table is placed in an upper housing member and the guide rod is positioned to a lower housing member and the upper housing member and the lower housing member engage with each other, whereby the guide rod is positioned relative to the guide section. If the positioning part of the guide rod and the guide section are thus largely away from each other on the structure and are placed in the separate members, it is difficult to improve the fit accuracy of the guide section and the guide rod.